We are using heatsink compound AND screws on the cooler-heatsink junction. My only concern was that the compound wasnt very good quality. Problem solved though! Flipped the fan, now blowing into the heatsink, and I can hit temperatures of 250+ without going over body temp. Right. Time for breakfast...by SanjayM - General
We are using screws through the fan/heatsink/cooler block to bind them tightly together. The fan is still sucking. Will try blowing instead shortly. Heatsink compound is being used - its white and greasy though - "Heat Sink Silicone Compound" with an 'SIL.MORE - Taiwan' logo. Is this stuff rubbish? On our heater block we use a 300C rated boron nitride heatsink compound between heater resistorby SanjayM - General
It 'strudes! All working and looking quite promising. We extruded PLA and ABS, and took it to a max temp of 320C for a short while. The cooler block did become noticeably hotter during use than previous prototypes. When extruding ABS at 230 the block, (very rough touch it and guesstimate) was around 30-40C and was around the uncomfortably hot 50-60 degrees when hitting 320. Extrusion forceby SanjayM - General
@theodleif Yup! The more we iterate, the closer we come back to what is basically a mashup of a RRP hot-end style, with a makerbot type PFTE-free break, all rearranged slightly to fit on a normal reprap. (We should mention, our first ever printer was a RRP Huxley, so this is probably no coincidence!)by SanjayM - General
@NumberSix Thanks! It is completely rock solid, we can stand on the frame happilly, and there is no way the forces of the axes moving are going to cause it to deflect in any way. I like the name 'hovercraft'! @Dark Alchemist The fan pictured on the extruder cooling block will not be controlled, there is no need as far as I can see, it just serves to keep the cooler-block cool at all times. Soby SanjayM - General
Righty! Here are some pics, its going together now, will probably be tested by the late hours of this evening, but I thought i'd post something asap to show you guys. Conclusions from discussion above and further thought: Two Fans are not needed. Having an always-on fan pointed at the print is not optimal. Getting all that gubbins under an X-Carriage is tricky. So! A bit of a revamp. Been buby SanjayM - General
NumberSix, Here's your video, complete with commentary. Theodleif, and others, Thanks for the feedback, we've been to the engineering firm, had a chat, we've come up with a more compact, single fan cooled, fan not aimed at bed design that we are quite pleased with. It makes everything cheaper, simpler, and lighter too. Putting one together ASAP for testing. Pictures to follow. We think you'by SanjayM - General
Hi NumberSix, Totally agree on the internal finish of the heat barrier, it is vital that it is smooth for the plastic in its 'rubbery' state to slip past. Also we find that the shorter the transition the lower the extrusion force, (less amount of 'rubbbery' filament sticking to the walls). We are looking at getting the heatbreaks reamed internally to a better finish to reduce friction. I like tby SanjayM - General
@Theodleif The break is around 2mm in length, I seem to remember getting about 3w or so as the number. - But your point still stands. Its not something I really have a satisfactory answer for, but the reality is that the heatsinks are lukewarm or so when printing, about body temperature (I really need to get an IR thermometer....). Hence the unwillingness to half the cooling. Two theories sprinby SanjayM - General
The fans do indeed bow towards the bed. We have contemplated reversing them to push air into the heatsinks, but this is obviously less efficient. We don't have any sticking issues, we print PLA on hot blue tape (overkill, but we don't mind the prising off, and like the extra sticking). We've printed ABS on: Kapton, (Some lifting of corners), Kapton+ABSJuice (Less lifting, adhesive on kaptonby SanjayM - General
Initially I did a fair bit of maths to determine the required heatsinking and decided on a single 40mm fan which we did manage to accommodate with a custom milled aluminium carriage design to which a 40mm heatsink and fan mounted directly. This obviously wasn't practical for use as a generic reprap hotend but we are still running it successfully on a prototype printer. The calculations were bornby SanjayM - General
As promised, here is the writeup for the hot-end, with lots of pics!by SanjayM - For Sale
As promised, here is the writeup for the hot-end, with lots of pics!by SanjayM - General
We've had a fair bit of interest in our other threads about our hot-end design so here is the promised write up. This design takes some fairly obvious cues from the RepRapPro and Makerbot MK7 style designs. Our goals were two-fold: No PTFE/PEEK # Limits maximum tempurature - so struggles with higher processing temp thermoplastics like PC # Degrades if accidentally overheated by a small margin (by SanjayM - General
Just acquired a bunch of DiBond CNC cut Y-Axis beds This stuff is amazingly stiff and extremely light, pretty much perfect for beds. Its aluminium clad so takes the heat without flinching. Really nice stuff.by SanjayM - General
Just a quick update, This machine has had its plywood bed platform replaced with a CNC cut DiBond (Aluminium PE Composite material) bed platform. This stuff is incredibly stiff and light, and doesn't warp under heat, so once your bed is level, it stays level.by SanjayM - For Sale
From what have experienced using this extensively, flow rate is adjusted so the bottom layer is not overstuffed. Very useful.by SanjayM - Slic3r
For reference it's now under the objects table in the plater tab once you add an STLby SanjayM - Slic3r
This could also be very useful for splicing together bits of gcode sliced with different properties to form objects with variable strength etc as required along Zby SanjayM - Slic3r
Hi Rich, We can sell you a fully cut/drilled frame in extremely rigid pressed PVC sheet. We have just put together a frame in the last 30 minutes from it, and it's awesome stuff. Quite heavy, but reassuringly so. You can screw into it with woodscrews without it cracking even with incredible torque. By the time it's CNC cut etc it isnt that cheap, but in the same range as acrylic etc. It is howeby SanjayM - General
Update: We have decided to list this printer on Ebay - The starting bid is down £100 to £850 now. You can still ask any questions here, or PM me for any other questions. We have some more prototype printers we are looking to tidy up and sell off soon also, so if you want something specific we can probably accomodate - so get in touch!by SanjayM - For Sale
Hi Evilb, We have prototypes, but they are not as extensively tested as the 1.75mm version. There is however very little difference and we are quite confident it should work. Are you wanting just a hot-end, or are you interested in the machine posted but would want it supplied with a 3mm hot end? Cheers, Sanjay and Daveby SanjayM - For Sale
For the past few months me and a friend have been severely bitten by the RepRap bug, 5 months later,and after having built 4 different printers (1 kit, 3 self-sourced) and having done quite a lot of research and testing we thought we'd share on the forums with a bit of a review of the build process for a Mendel90 and hopefully incite some discussion about the design in general. Firstly, a big tby SanjayM - General
Cheers Nophead! Approval from the man himself means a lot to us! Any other thoughts? Just to be clear, as I can see people might get the wrong idea from the post above, this ad is for the one-off printer in the photos, we are not yet doing a production run of assembled machines or anything like that. It's a machine we put together to verify our designs for hot-ends etc that we are selling off jby SanjayM - For Sale
Hi All, We are a small 2 person start-up in the UK, we've built quite a few printers, for ourselves and friends but are now looking to start selling to the wider world. Here is our Mendel90 (Original design by nophead, detailed on his excellent blog) that we are now offering for sale. We have pulled out all the stops on this one, and really think it is one of the better available machines inby SanjayM - For Sale
No real reason why you can't just pull out the Step and Direction signals from the ramps board where they would normally enter the pololu carrier and just running them to any other Step/Dir motor driver chip (Almost all are step/dir anyway). You should also obviously be supplying the 48v separately to the drivers, and feed RAMPS its 12v. Shouldnt be much hassle, Buy beefy driver Buy beefy poweby SanjayM - RAMPS Electronics
Incredible, Registered at these forums for this thread... Really impressed, I think this design is going places. My grasp of the coordinate system here is weak, when you quote 30steps/mm in X/Y is that resolution constant across the whole range of movement, or does it vary like a polar/SCARA type bot?by SanjayM - Delta Machines